Mayo said that Morgan Stanley had become leaner and meaner since its Dean Witter acquisition 16 years ago as well as its Smith Barney acquisition. Cost-cutting and a $20 billion increase in deposits would also lead the stock higher, he added.
"Their margin improved during a weak seasonal quarter, so you have more good news to come," Mayo said.
(Read more: Morgan Stanley earnings, revenue top expectations)
Mayo said that he still liked Goldman Sachs, adding that its lackluster earnings results were "probably a one-quarter miss."
But JPMorgan wasn't attractive to him.
"I see it as dead money at best," Mayo said, citing pending legal woes and a likely multibillion-dollar settlement ahead. "But you could still have a hangover, even after that settlement. And it's up to (CEO) Jamie Dimon and JPMorgan to make sure they get a fair deal for shareholders."
(Read more: UBS sees IBM as 'dead money')
OptionMonster's Pete Najarian saw it differently.
"Totally disagree," he said. "Completely disagree with that statement.
"I don't think it's dead money. I think you've got plenty of upside there. When this thing starts to really return some of that money back, I think JPMorgan can outperform some of the other banks, actually including the Wells Fargos that are a lot more of a steady earner type, the type that's going to be a steady-Eddie beta trade."